Flagellar transcription profile of the ΔflgT mutant. C6706lacZ (wild type) and the ΔflgT mutant (flgT) carry multicopy plasmids containing the indicated promoter in front of lacZ. Beta-galactosidase activity was measured from bacteria in midlog growth phase. Expression from class I and class II promoters (flrAp, flrBp, fliEp) remain at wild type levels in the ΔflgT mutant and expression from class III promoters is normal (flhAp) or elevated (flgKp, flaAp). Transcription from class IV promoters (flaBp, flaCp, flaDp) is strongly repressed in the flgT mutant.